Epic win

Trouble is that London is covered in CCTV, you wouldn't get anywhere close to finished before you got nabbed.

Hmm, if you got loads of people on bikes though, and they had all practiced at doing one bit each, all at the same time..

Anyone?

You'd just need 4 cyclists, one going each way, one to do a U-turn and one to do the line across, all ride off, job done